The present invention relates to an IC handler able to transfer an IC device. Particularly, it relates to an IC handler able to rotationally transfer an IC device.
As an IC handler which transfers an IC device to an IC socket and removes an inspected IC device from an inspecting device, a pick-and-place type, a rotary index type, and a cam index type are well known.
An electric cable or an air tube is often attached to the IC handler to supply energy, such as electricity or compressed air, necessary to carry out a rotating operation or a clamping operation. An index table using a number of cams are used to prevent the electric cable or the air tube from being twisted during operation. In the index table, cam surfaces are locally worn in proportion to the period of use, and the worn portion results in chattering, and reduces the positioning accuracy, thus leading to overrun or the like, or breakage of the IC device to be inspected or the IC socket.
In an IC handler which rotates only in one direction, the attachment of the electric cable or the air tube is complicated and expensive. Accordingly, a number of cams are used to clamp the IC device when inspection. However, it is difficult, in such a IC handlers, to make a fine adjustment and to easily adjust the pressure to be applied to an optimum value.
Thus, the IC handler in which the pressure applied to the clamper cannot be adjusted, or in which there is no function to prevent overload, has a problem that an inspection measuring board can be damaged when two overlapped IC devices are abnormally supplied. Moreover, there is a possibility that when a plurality of IC devices which are aligned and supplied at one time are inspected by means of an U-shaped spring probe, the latter cannot sufficiently absorb irregularity in height of the IC socket or in thickness of the IC device. Also, recent spring probes whose compression stroke is short sometimes cannot be used.
In view of the above problems, the object of the present invention is to provide a simple IC handler in which wear tends not to occur, so that the accuracy can be maintained for a long time.
Another object of the present invention is to make the applied pressure adjustable.
According to the present invention, there is provided an IC handler, comprising
a disk which is rotatably supported in a horizontal plane;
two controllable motors disposed on an upper surface of the disk;
two driving shafts that downwardly extend through the disk, and that are driven by the two motors respectively, said driving shafts being disposed symmetrically with respect to an axis of rotation of the disk;
two hanging members that are engaged with the two driving shafts respectively via driving force converting mechanisms, and that are upwardly and downwardly moved by the rotation of the driving shafts;
a clamper attached to a lower end of each of the hanging members;
a suction pads attached to lower ends of the clampers; and
a disk driving motor that can rotate the disk in a first rotational direction and a second rotational direction opposite to the first rotational direction, wherein
after the disk is stopped at a first angular position for a predetermined period, the disk is rotated in the first rotational direction, to a second angular position which is deviated from the first angular position by 180 degrees, by means of the disk driving motor and, after the disk is stopped at the second angular position for a predetermined period, the disk is rotated, in the second rotational direction, to the first angular position;
during the stop at the first angular position, the clamper engaged with one of the driving shafts carries out a first operation, and the clamper engaged with the other driving shaft carries out a second operation; and
during the stop at the second angular position, the clamper engaged with said one driving shaft carries out the second operation, and the clamper engaged with the other driving shaft carries out the first operation.
According to an embodiment of the present invention, a pneumatic cylinder is provided above the clampers; and pressurized air is supplied from an air pressure supplying means to the pneumatic cylinder via a pressure regulator which can finely adjust the pressure.
According to another embodiment of the present invention, the disk driving motor is located on the outside of the disk and rotates the disk via a belt.
Embodiments of the present invention will be described below with reference to accompanying drawings.